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  #11  
Old 05-05-2019, 06:46 PM
Mconner7 Mconner7 is offline
 
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Thanks Tim,
Those speeds make sense and are easily kept within. At the mid to upper teens, the indicated speeds are well below this limitation. It is nice to know what flap settings are most efficient.

Mark
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  #12  
Old 05-05-2019, 06:47 PM
scsmith scsmith is offline
 
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It is not too surprising that the airfoil works a little bit better at zero (trail) when at high altitude and loaded heavy. The reflex position should give higher speed down low, and at average loading.

BTW, I am the designer of that airfoil.
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  #13  
Old 05-07-2019, 08:25 AM
AviatorJ AviatorJ is offline
 
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Quote:
Originally Posted by Tim Lewis View Post
Fully retracted flap position (reflex) is defined on page 44-5 of the plans, where the flap inboard leading edge makes solid contact with the rear spar doubler plate. From what I've seen, the bottom of the flap is slightly above the bottom of the fuselage in this position.
I honestly had issues with that method. I ended up using a digital leveler to get the 3% and you are correct it about 1/16th higher.

Quote:
Originally Posted by Tim Lewis View Post
The 122 knot limit is not arbitrary. The RV-10 Construction Manual, page 21, lists the flap limit speeds. 140mph (122 knots) for trail, 110 mph (95 knots) for 1/2 flaps, 110 mph (87 knots) for full flaps.
I missed that. I had seen 1/2 and full flap but honestly thought people just assigned random numbers for trailing. At least on my plane it seems to support a much higher number with no flutter or control issues.

Thanks for the info
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  #14  
Old 05-07-2019, 10:23 PM
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M McGraw M McGraw is offline
 
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Location: Greenback, TN
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Quote:
Originally Posted by scsmith View Post
It is not too surprising that the airfoil works a little bit better at zero (trail) when at high altitude and loaded heavy. The reflex position should give higher speed down low, and at average loading.

BTW, I am the designer of that airfoil.
Near gross weight, at what altitude would you expect the flaps zero (trail) to begin increasing the cruise speed.

A guess from the designer could save me an hour or two of testing, because I’m gonna try.
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Last edited by M McGraw : 05-08-2019 at 12:05 AM.
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  #15  
Old 05-08-2019, 11:46 AM
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RV8JD RV8JD is offline
 
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Quote:
Originally Posted by Tim Lewis View Post
The 122 knot limit is not arbitrary. The RV-10 Construction Manual, page 21, lists the flap limit speeds. 140mph (122 knots) for trail, 110 mph (95 knots) for 1/2 flaps, 110 mph (87 knots) for full flaps.
Quote:
Originally Posted by AviatorJ View Post
I missed that. I had seen 1/2 and full flap but honestly thought people just assigned random numbers for trailing. At least on my plane it seems to support a much higher number with no flutter or control issues.
How about the flap control system loads?
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Last edited by RV8JD : 05-08-2019 at 11:50 AM.
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  #16  
Old 05-09-2019, 09:52 PM
Mconner7 Mconner7 is offline
 
Join Date: Feb 2018
Location: Bradenton FL
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Quote:
Originally Posted by scsmith View Post
It is not too surprising that the airfoil works a little bit better at zero (trail) when at high altitude and loaded heavy. The reflex position should give higher speed down low, and at average loading.

BTW, I am the designer of that airfoil.
Thanks for a great wing. I marvel at how efficient it is at high altitude despite its low aspect ratio.

Mark
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  #17  
Old 05-18-2019, 09:02 AM
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ScottSchmidt ScottSchmidt is offline
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Location: Salt Lake City, Utah
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Default Flap Speed

According to this post Van's lifted the speed restriction for first notch (-3 to 0)

"I had a conversation yesterday with Vans regarding flap speeds. As most of you know, Vans published Flap speeds for the -10 are as follows:

"FLAP SPEED: On the RV-10, 140 mph statute for “trail” (3º deflection), 110 mph statute for “½ flap” (18ºdeflection), and 100 mph statute for “full flap” (33º deflection)."

According to Vans Tech support, engineering has decided through analysis and/or testing, to eliminate the speed restriction for the 0 degree "in trail" position of the flaps. They had no idea when the documentation would be changed to reflect this new data."
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Last edited by ScottSchmidt : 05-18-2019 at 09:05 AM.
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